Advice for keeping 9-month-old occupied on long car ride?

I'm driving my son (alone) to my parents' house about 5 hours away for Christmas. The last time I took him, he was 3 months old and screamed bloody murder for the full last half of the trip as long as he was strapped into his car seat.

Now that he's bigger, I suspect things could be even worse since he now has a rudimentary concept of what boredom is (and has more powerful lungs to let me know!)...and I don't love that feeling of uncertainty Does anyone have suggestions for things to keep him occupied while we drive? Any particular toys your kids love and don't throw all over the back seat of the car? We have one of those seat mirrors, but he doesn't really care about it...it's more for us.

We did a 7 hour drive today and we left at 4am. I nursed Lo and we put her in the car in her pjs and she slept for 4 hours. Then we stopped, changed her, fed her and she played and went back to sleep for the last hour. My advice is leave either when Lo is tired around a nap or the middle of the night.

If you are traveling with someone else, I'd recommend having someone next to LO on the way. That way they can be in control of any toys--toys can become projectiles in the event of a car accident. So the softer the better. The rule of thumb is is you wouldn't throw it in your baby's face, it's not a great idea to have back there.

Also, rear-facing is best for kids. I plan to rear-face til age 4. Current AAP recommendation is til 2 and NSHTA is til 4. Here's a link on why rear-facing is 534% safer: carseatblog.com/5168/why-rear-facin...